Last week we started getting ready for Win 11 Ent on Horizon 8 (on prem VDI).
Found this post because we're having same issues.
Menus / right-click anomalies in file explorer where eventually is just blank.
Some options also disappear when going over with the mouse pointer.
Besides restarting Windows Explorer in task manager, which does not last problem free, trough trial and error / multiple testing scenarios where this problem does not resurface we found that the only fix at this time may be replacing VMware SVGA 3D Driver with Microsoft Basic Display Adapter.
We have 3D software rendering, other vDesktops are fine, Win 11 is not until this driver change.
FYI, we're still in testing mode so not sure what the impact is for watching training videos or Teams meeting with cameras by going with Microsoft Basic Display Adapter.